Metal arc box for fuses



Feb. 2, 1932. w. R. TALIAFERRO 1,843,583

METAL ARC BOX FOR FUSES Filed Aug. 22, 1928 Fig. 1.

INVENTOR W 22 Zz'am RT'aliaferro.

ATTO'RNEY Patented Feb. 2, 1932 u-UNITED STATES PATENT. OFFICE WILLIAM R. TAIiIAFERRO, F PITTSBURGH, PENNSYLVANIA, ASSIGNOR '1 O WESTING- HOUSE ELECTRIC & MANUFACTURING COMPANY, A CORPORATION OF'IPENNSYL- VANIA Application filed August 22, 1928. Serial No. 301,250.

My invention relates to arc chutes or boxes and more particularly to an arc box for an expulsion type fuse.

One object of my invention is to provide a closure member for the end of an expulsion fuse that shall prevent the flame or the expelled portions of the fuse from passing out of the structure.

Another object of my invention is to provide an arc box of the above-described type that shall be constructed entirely of metal except for the insulating portions employed to mountthe fuse structure within the closure member.

' Difiiculty has often been experienced in employing the expulsion type fuse due to the ejecting .of portions of the fuse structure and the hot metals upon adjacent circuits or apparatus causing short circuits or other damage. Difiiculty has also been experienced because of gases being propelled along the outer surface of the fuse forming an ionized path causing the arc to restrike between the terminals thereof or in a grounded system, between ground and the line terminal.

' My invention overcomes these objectionable features of the expulsion type fuse by providing the expulsion end thereof with an arc box of such form as to prevent ejected gases from ionizing the space between the terminals of the fuse.

My invention will best be understood from the following description having reference tothe accompanying drawings, in which:

Figure 1 is a diagrammatic view of a circuit connected to an expulsion fuse embodying the features of my invention shown in 1 section; and,

Fig. 2 is an end view thereof in elevation.

I My invention comprises, in general, an ex pulsion type fuse 1 that has one end within the arc box 2 and supported therein by a par- ;15 tition 3 that prevents the escape of gas and the formation of an ionized path between the terminals of the fuse 1.

The expulsion fuse 1 is of the conventional type having its expulsion end, from which the fuse element 4 extends, located within the box 2'. Within the outer casing of the expulsion fuse 1, a secondary tube containing a metal portion (not shown) is located and is employed to assure overload operation of the fuse structure.

The are box 2 is constructed of metal to increase the life and strength thereof and atthe same time to reduce its cost. The end 3 adjacent the fuse 1, is formed of insulation and has a line terminal 5 and a fuse terminal 6 mounted thereon by the bolt 7 The opposite end is covered by a wire gauze '8 to permit the escape of the evolved gases and to-deionize the flame that may be projected therethrough.

A portion 9 of the top of the are box 2 is hingedly attached thereto by hinges 10 and is employed as a means ofingress tothe box in order to adjust or renew the fuse element 4. The meta-lbox 2 is grounded by means of aground wire 11 that is attached thereto by a rivet 12 and is employed to reduce the hazard to an operatorwho might come in contact with the box when the fuse is in process of being ruptured.

A circuit is shown diagrammatically including a generator 13, one terminal of which is connected to a load 14-, the line then continuing to the terminal 5. The other terminal of the generator 13 is connected to the grounded terminal 15 of the fuse 1.

When an overload occurs in this circuit, the fuse will be ruptured and the overload tube of the fuse structure 1 will be ejected into the arc box 2 along with the gases and the hot particles of the fuse element 4 and the circuit will thus be broken without any danger of the are being reignited by gases between the fuse terminals or any danger of damaging neighboring apparatus by the ejected material.

The figures of the drawings show the end of the expulsion fuse projecting into the arc box. Tests have shown that this is not always necessary, as my invention operates successfully under certain conditions when the end of the fuse is outside the box but so posiin providing a partition throughv which the fuse or the materials pass and which prevents the egress of gas, thereby preventing the formation of an ionized path between the terminals such as'would cause the arc to restrike. By the employment of the gauze screen over the end of the arc box adjacent the expulsion end of the fuse, the gases evolved when the fuse blows are permitted to escape under such conditionsas to be dei0nized.

I do not wish to be'limited' to the particular construction herein shown, as many changes, additions, subtractions or substitutions may be made withoutdeparting from the spirit of the invention. I, therefore,- do not wish my invention to be limited to any structure except as set forth in the appended claims.

I claim as my invention:

1. In combination, an arc box," an expulsion fuse therefor, said are box being constructed of metal and'having an insulating portion adjacentthe expulsion end of the fuse.

2. In combination, a metal arc box, an expulsion fuse therefor, the expulsion end-of the fuse extending withinthe box.

3. An are box of metal, an expulsion fuse extending within said box, an insulating member in one'portion of the box, a terminal on said insulating member connected to the fuse end extending within the box.

LA metal are box for an expulsion fuse having the expulsion end of the fuse extending within the box and means for grounding the box.

5. An arc box of metal for an expulsion fuse, an insulating member in one portion of the box having a terminal thereon connected to the fuse end extending within the box and a wire screen covering an opening oppositeto the fuse end.

6. An arcbox for a fuse constructed of metal and having insulatingmeans associated therewith for supporting one end of thefuse and a'wire gauze. covering one side of the box.

7. An, enclosing chamber fora fuse constructed of metal and having insulating means associated therewith for supporting scribed my name this 17th day of August WILLIAM R. TALIAFERRO. 

